Tripod



Feb. 10,1942.

H. J. WAECHTER TRIPOD Filed May 14, 1940 Patented Feb. 10, 194-2 N O F Fl C TRIPOD Applicationll Iay 14, 19 A), SerialNo. 335,097

Claims.

This invention relates generally to foldable tripods of the typeutilized for music stands, telescope rests, camera rests and the like.More particularly, it is concerned with the combination and relationshipof the legs, their links and, the lower section of the standard.

It is naturally desirable in ioldable stands to have the leg structureslock against collapse under weight while in any degree of spread. Thetypes now in use are provided with manually operated locking means suchas thumb screws or split rings which lock under the influence of cams.

The present invention provides a stand which requires no locking meansto sustain its legs in position when unfolded and set up. Consequently,no manipulation of thumb screws or other detent means is necessary tochange the position of its legs. Furthermore, the invention incorporatesa simple means for limiting the spread of the legs beyond theireffective selfsustaining extreme.

It has, therefore, been an object of this inventor to provide a stand ofsimple structure which is self-sustaining against collapse, that is,without the use of detents, at any point in the eiiective spread of itslegs.

Another object of the inventor has been to provide a stand whichutilizes a minimum of ,parts without losing any structural strengthbecause of its simplification.

Furthermore, it has been another object of the inventor to utilize apost formed of triangular tubing and to arrange the lugs of the runneror the case element so that they project radially from the points of thetriangular tubing. Thus the supporting thrusts or pressures exerted bythe legs or links are directed against portions of the post which arebraced. In other words, a post of this cross-section, with the lugsarranged as described, is much less apt to collapse than theconventional round tub-ing. Also, there is absolutely no possibility ofthe post sections rotating one within the other, and no chance of therunner rotating on the post, which rotating action in the case of therunner would permit twisting of the tripod structure.

Other objects and advantages of the invention will be apparent from thefollowing description of the drawing in which:

Fig. 1 is a side view of a music stand embodying the invention.

Figure 2 is a cross sectional view taken on line 22 of Figure 1.

Figure 3 is a View looking up toward the bottom of the standardillustrating the manner in which the inner ends of the links areutilized as stops to limit the extension of the legs of the stand.

Figure 4 is .a view of the blank which forms the runner or base piece.

Figure 5 is a diagrammatic view of a stand illustrating theself-sustaining action of the parts.

Figure 6 illustrates the legs of the music stand as they appear whenfolded.

The standard, indicated generally at in, consists of several tubularsections which telescope to provide adjustment of its height. A musicrack II carries a post i2 which slides into the upper section of thestandard. The standard shown in the drawing is made of tubing which istriangular in cross section. Cylindrical tubing may be utilized withoutdeparting from the spirit of the invention except wherein the inventionpertains to the self-supporting arrangement of the legs and links.

The supporting base, to which the invention is particularly directed,consists of the lower section l3 of the standard It), a foot piece M, arunner l5, legs It, and links l1. The foot piece and runner may be madeidentical to simplify their fabrication. Both the runner and foot piececomprise a-body portion I8 and three arms I9 which extend radially fromthe body portion. The blank from whicheither the foot piece or runnermay be madeis shown in Figure 4 of the drawing.

To form these ports so that they fit around the triangular standard,three folds, along the dotted lines 29, are'made in the body portion [8-of each blank to bring side edges 2i and 22 together. The arms iii arefolded along the lines 23 to extend downwardly and radially from thethree corners of the triangle as shown in Figures 2 and 3. The footpiece is secured near the bottom-of the standard by spot welding or somesimilar method, While the runner is placed around the standard above thefoot piece so that it is free to slide up and down.

Each leg I6 is pivotally attached to its corresponding arm I9 of theslidable runner by a pin 24. Each link I! is similarly attached to anarm of the stationary foot piece by a pin 25. A short end section 26 ofeach link extends inwardly beyond the pivot point 25. 'The other end ofeach link is pivotally attached to its corresponding leg by a pin 21.

The essence of the invention resides in the relationship of the axes ofthe pins 24, 25, and 2'1, and the end sections 26 of the links, to thelower section of the standard. In the preferred embodiment of theinvention, the length of each link between the centers of pins 25 and 21is approximately .95 or a little less than the distance between thecenters of pins 24 and 21 on the legs. Preferably, the distance betweenthe centers of pins 24 and 2'! is substantially less than one-half thetotal length of each leg. In Figure 1, the bracket a defines the travelof the runner through the efiective distance of the selfsustainingaction of th leg structure.

The diagram in Figure 5 illustrates the manner in which the partscooperate. It can be seen from this diagram that the standard is free tomove relative to the runner. The links take the direct thrust of anyweight that is placed on the stand and transmit th weight to the legs sothat the runners take the thrust of the upper end of the legs, and thesurface upon which the stand is resting takes the thrust of the lowerends of the legs.

If the runner were permitted to be moved downwardly far enough to bringthe links to a position where they are at 90 degrees to the axis of thestandard, the distortion in the metal of the parts and the looseness ofthe joints would permit the links to sag or fold slightly if weight wereplaced on the stand. Since the above described sag would occur only whenthe links are near the horizontal, i. e. 90 degrees to the axis of thepost, a limit to the spread of the legs is provided to prevent the linksfrom moving to positions in which they are at 90 degrees to the axis ofthe post. Therefore, the stand is positively set against movement at anypoint in the possible spread of the legs.

This limit is constituted by the sections 26 of the links. In Figures 1and 3, it can be seen that the sections 26 extend inwardly to contactthe bottom of the standard when the effective limit of the spread of thelegs is reached. In the stand illustrated, this effective limit isreached when the links are disposed approximately at 80-85 degrees tothe axis of the post. The self-sustaining action of this structure ispositive in any degree of spread of the legs and the runner will notslip under any weight; the only limiting factor to the weight that thestand will support being the structural strength of the parts utilized.

Having described my invention, I claim:

1. Tripod means for supporting a post, comprising; a runner slidablymounted on the post, a base element of the same form as the runner butfixed to the bottom of the post, said runner and base elementrespectively including radially extended ears, legs pivotally connectedto therespective ears of the runner, links pivotally connecting the earsof the base element to intermediate portions of the legs, said linksincluding portions extending inwardly beyond their pivotal connectionsto the base element, said extensions adapted to engage the lower end ofthe post and constituting stop means effective for stopping downwardswinging movement of the links before they reach horizontal position,the distance between the pivotal points of the links being slightly lessthan the distance between the pivotal points of the legs and theconnection of the links thereto.

2. Tripod means for supporting a post, comprising; a runner slidablymounted on the post, a base element of the same form as the runner butfixed to the bottom of the post, said runner and base elementrespectively including radially extended ears, legs pivotally connectedto the respective ears of the runner, links pivotally connecting theears of the base element to intermediate portions of the legs, saidlinks including portions extending inwardly beyond their pivotalconnections to the base element, said extensions adapted to engage thelower end of the post and constituting stop means effective for stoppingdownward swinging movement of the links before they reach horizontalposition.

3. Tripod means for supporting a post, comprising; a runner slidablymounted on the post, a base element fixed to the bottom of the post,legs pivotally connected to and extending radially from the runner,links pivotally connecting the base element to intermediate portions ofthe legs, said links including portions extending inwardly beyond theirpivotal connections to the base element, said extensions adapted toengage the lower end of the post and constituting stop means effectivefor stopping downward swinging movement of the links before the linksreach horizontal position, the distance between the pivotal points ofthe links being approximately .05 less than the distance between thepivotal points of the legs and the connection of the links thereto.

4. Tripod means for supporting a post, comprising; a runner slidablymounted on the post, a base element fixed to the bottom of the post,legs pivotally connected to and extending radially from the runner,links pivotally connecting the base element to intermediate portions ofthe legs, said links including portions extending inwardly beyond theirpivotal connections to the base element, said extensions adapted toengage the lower end of the post and constituting stop means efiectivefor stopping downward swinging movement of the links before they reachhorizontal position.

5. A post supporting tripod including a post of triangularcross-section, a runner of triangular cross-section freely slidablymounted on the post, ears fixed to and extending radially from the lowerend of the post, said triangular runner including ears extending fromits corners, said last-named ears disposed along lines exactlyintersecting the angles formed by the sides of the post, legs pivotallyconnected to and extending from said last-named ears in parallelismtherewith and links pivotally connecting intermediate points of the legswith said first-named ears.

HARRY J. WAECHTER.

